How Does AC Work?​

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Image of a rooftop condenser unit, a key component in HVAC systems, installed on top of a commercial building against a clear sky. The metal casing and cooling fans are visible, symbolizing the essential process of heat exchange in air conditioning.

How Does AC Work?​

How Does AC Work?

From Refrigerant to Room – A Comprehensive Guide to Air Conditioning

Understanding HVAC

Air conditioning is not only a marvel of modern comfort but a fascinating piece of history. Invented by Willis Carrier in 1902. air conditioning allows us to escape the hot summers, especially in bustling Los Angeles County. But have you ever wondered how AC works, or what’s behind the refreshing cool air in your home or business? In this comprehensive guide, we’ll break down the process, step by step, from the condenser to the registers inside your space, to help you understand the essential components. 

Carrier has an expert article on this check it out on their site here.

Ready to experience  comfort with your air conditioning? Whether you need maintenance, repair, or a whole new system in Covina and surrounding areas, our expert team is here.

Step 1: The Refrigerant – The Heart of Cooling

The air conditioning journey starts with the refrigerant, a solvent made of Chlorofluorocarbon (CFC) that circulates through the system. This special compound changes states from liquid to gas, absorbing heat from your home’s inside air and releasing it outside. Refrigerants like 407C and 410A are commonly used and added to the system through the condenser outside. They are then pumped to the evaporator coil through the compressor, setting the stage for the cooling magic to begin.

Step 2: The Compressor - Pressurizing the Refrigerant

Next, the compressor steps in, playing the vital role of pressurizing the refrigerant and turning it into a hot, high-pressure gas. This transformation is essential for transferring the collected heat from the inside of your home to the great outdoors, enabling the cooling process to start.

Step 3: The Condenser - Cooling Down

At the condenser, the story unfolds further. The hot refrigerant gas releases its captured heat to the outside air, transforming back into a cooler liquid form. Heat is released at the condenser after it’s cycled through the evaporator coil inside your home, setting the stage for even further cooling and comfort.

Step 4: The Expansion Valve - Regulating Flow

The process continues to the expansion valve, where things take a controlled and precise turn. This critical component regulates the refrigerant’s flow, allowing it to expand and cool down further. This essential step prepares the refrigerant for the next vital phase: the evaporator coil.

Step 5: The Evaporator Coil - Absorbing Heat

Inside your home, the evaporator coil acts as a heat magnet. The refrigerant passes through, absorbing heat from the inside air and turning into a gas once again. This transformation cools the air and sets the stage for a comfortable environment. The success of this whole process relies on the proper pressure testing of the Freon during AC installation, a step that ensures efficiency and reliability.

Step 6: The Furnace - Blowing the Air

Most people may not associate the furnace with air conditioning, but this perception is far from the truth. The furnace’s fan plays a key role in blowing the chilled air into the ductwork, ensuring it is evenly distributed throughout your home, enhancing comfort in every room.

Image of a modern furnace, showcasing the sturdy metal construction with vents and control panels. The furnace is often located in a utility room or basement and plays a vital role in heating a home during colder months, as well as circulating cool air from the air conditioning system
Furnace being installed in a garage in San Dimas

Step 7: The Ductwork - Moving Air to Different Rooms

The final act is carried out by the ductwork, acting as the grand conductor, orchestrating the movement of cooled air to various rooms in your house. Proper ductwork installation ensures a consistent and comfortable temperature in every space. Even a small rip in your ductwork could release cold air into your attic, creating inefficiencies and increasing your electricity bill. Therefore, regular maintenance is vital for optimal performance.


Air conditioning is more than a luxury; it’s a complex mechanical process with lots of moving parts and a rich history. From the initial cooling of the refrigerant to the final distribution of chilled air throughout your home, it’s a fascinating journey of engineering and temperature control. Understanding these seven steps can empower you to maintain your AC system, ensure its efficiency, and truly appreciate the comfort it brings to your life in the hot summers of Los Angeles County.

For any assistance or inquiries about your HVAC system in Los Angeles County, don’t hesitate to reach out to our expert team. We’re here to keep you cool, informed, and comfortable!






Ready to dive deeper into understanding air conditioning systems? Check out our comprehensive “Guide to Understanding AC Systems, Installation, and Types”. Gain expert insights on selecting the right AC system and ensuring a hassle-free installation in LA County!

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